1. Field of the Invention
The present invention relates generally to a sleep-preventing alarm system. The invention is, however, more particularly directed to a grip responsive sleep alert system and method, for providing an audible alert to preclude a driver of a motor vehicle or any other user from falling asleep with a sleep-preventing alarm.
2. Description of the Prior Art
Driver fatigue and falling asleep at the wheel is a major cause of car crashes. Fatigue can be very difficult to identify as the source of accidents because estimates are made based almost solely on police reports and driver statements. Estimates are that 10-20% of fatal accidents and about 5 to 10% of all car accidents may be related to tired drivers.
According to the National Highway Traffic Safety Administration, there may be as many as 100,000 crashes resulting from driver fatigue each year, with an estimated 1,550 deaths, 71,000 people injured, causing $12.5 billion economic losses. These figures may be the tip of the iceberg, since currently it is difficult to attribute crashes to sleepiness.
In accordance with a recent survey, more than 10 percent of drivers admit to having fallen asleep at the wheel, while more than 20 percent say they have momentarily dozed while driving, according to a study of 1,024 drivers. Referred to as “the silent killer” because it is so often overlooked as the cause of an accident, drowsy driving's full effect is not yet known because reporting is imprecise, police are not trained to detect sleep-related crashes and there is no device to determine whether someone was driving while dangerously drowsy.
Some of the tactics drivers resort to in an effort to fight drowsiness on the road are, in descending order, stop driving or switch drivers, open the windows or turn on the air conditioning, listen to the radio or CDs, stop eating or drinking, drink caffeine, among others.
Another method drivers have used to stay awake at the wheel include talking or singing to themselves, splashing water in their faces and slapping, hitting, or pinching themselves.
Sleep deprivation is a common problem not only for car drivers but also among airline pilots and other workers who are required to perform any type of tasks over a prolonged period of time. Just as an example, on Mar. 4, 2004, a commercial pilot and his first officer fell asleep while approaching Denver International Airport in an A319 Airbus jet, going twice the speed as allowed, according to a report from the Federal Aviation Administration (FAA).
Loss of sleep and fatigue in these settings can significantly impair cognitive function, and can lead to dangerous decrements in human performance. In particular, falling asleep at the controls of a commercial vehicle such as a truck, tanker, or airplane can lead to potentially catastrophic consequences. Besides the transportation context, drastic consequences may result by an operator falling asleep at the controls of a nuclear power plant, an electrical power grid, or other system that could impact many lives.
There are several patents in the prior art related to devices and methods for providing an audible alert to the user. For example, a sleep alert apparatus adapted to be worn upon the head of the operator of a transportation vehicle includes a baseball-type cap, a flexible pouch attached to the exterior surface of a side portion of the cap, an upwardly directed entrance opening, and a tilt monitoring device removably inserted into the pouch. The tilt monitoring device includes a housing confining a gravity activated switch, a noise generator, and a battery power source.
Another example is a fatigue alarm comprising a housing, with the housing including a first fixed handle plate extending from the housing and a second movable handle plate separated from the first handle plate in a biased separation relative to one another, such that a first electrical contact secured to the second handle plate within the housing is in contiguous communication with a second electrical contact within the housing in a normal configuration, such that upon separation of the first electrical contact relative to the second electrical contact against a spreader member within the housing effects disengagement and deactivation of an audible alarm, whereupon fatigue permits movement of the second handle plate away from the first handle plate to engage the first electrical contact and the second electrical contact to actuate the audible alarm to alert an individual at an onset of sleep.
There is also an apparatus known which decides the presence or absence of an anomaly by detecting the gripped state of a steering wheel by the driver steering a road vehicle, or by measuring fluctuations in the heart rate and heartbeat period of the driver, and which issues an alarm of “Take a rest”, etc. or control the vehicle speed to be lowered, if any anomaly occurs. A detecting means is attached to a steering wheel, steering wheel cover or a band-shaped member. The detecting means comprises a plurality of reflection type optical sensors, which are each composed of a light emitting element and one or lighter receiving elements, and which are set in such proper arrangement and orientation as to permit detection in any of various conditions.
An alarm system formed by a wrapper includes an energy source, an operator grip pressure controlled switch, an orientation responsive switch, and an audio resonator is also known. The wrapper is secured to an operator controllable member, such as a steering wheel, by being folded over the member upon itself and secured using, for example, a fabric fastener interlock. In operation, the user places his/her hand upon the pressure control switch included within the wrapper. When the grip of the user becomes relaxed, for example, due to inattention or fatigue, the switch operates the resonator and an alarm is sounded. The orientation responsive switch controls disablement and enablement of the alarm system in response to displacement of the operator controllable member.
Another grip responsive alert system includes a pressure sensor associated with a mechanism for controlling a vehicle. The pressure sensor detects operator fatigue as exhibited by a change in operator pressure on the control mechanism. An operator stimulus is coupled to the pressure sensor and, upon sensing fatigue, produces a stimulus such as a visual or audible alarm whereby alertness of the operator is maintained.
The above cited solutions are basically focused on waking the driver, but this is not an appropriate solution to this serious problem. Just as an example, a vehicle traveling at 60 miles per hour (MPH) goes 88 ft. per second, almost a football field every 4 seconds. Sleep must be prevented instead of waking a driver.
Those devices for detecting the movement of the driver's head involve a delay needed to run the process that it is not acceptable. Every road has a crown for water runoff. On a common one lane each way road, the crown is in the middle, therefore when the driver falls asleep, the vehicle is directed to steer slightly left. Every vehicle has the front wheel geometry adjusted to causing the vehicle to travel in a straight line when there is no driver physical input. That would be fine if the driver only travels across two-lane roads. However, if the driver is on a four or more lane road, the steering geometry increases a left steering action, and a crossover accident may be imminent.
Even though the above cited systems and devices for awaking an operator address some of the needs of the market, an economical and simple sleep alert system to prevent the operator from failing asleep, may be used by different type of users, including car drivers, airline pilots, security personnel, among others, is still desired.